A large number of solar heating systems have been suggested heretofore. The most relevant patents known to me are U.S. Pat. Nos. 2,425,775; 3,893,506; 4,000,850 and 4,000,851. While a great deal has been written about solar heating systems, I believe the most relevant is a book entitled "Solar Energy And Building" by S. V. Szokolay.
I believe a major defect of prior systems is the lack of the concept of using the solar heating system as an integrated part of the architecture of the building. This invention is a solution to that problem whereby the walls of the building perform a dual function, there is no need for a large water storage tank, etc.